feat(clock): remove theme setting

- Remove theme from screenly.yml and screenly_qc.yml manifests
- Remove theme entry from README configuration table
- Remove theme from e2e screenshot mock settings

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: nicomiguelino

edge-apps/clock/README.md

@@ -25,7 +25,6 @@ The app accepts the following settings via `screenly.yml`:
 | `openweathermap_api_key` | OpenWeatherMap API key to access weather data and location information. Get your API key from the [OpenWeatherMap API](https://openweathermap.org/api)        | optional           | -       |
 | `override_locale`        | Override the default locale with a supported language code                                                                                                    | optional           | `en`    |
 | `override_timezone`      | Override the default timezone with a supported timezone identifier (e.g., `Europe/London`, `America/New_York`). Defaults to the system timezone if left blank | optional           | -       |
-| `theme`                  | Visual theme for the app: 'light' or 'dark'                                                                                                                   | required           | `light` |
 | `unit`                   | Measurement unit for temperature display: `auto` (automatically determined based on location), `metric` (Celsius), or `imperial` (Fahrenheit)                 | optional, advanced | `auto`  |
 
 **Note:** When `unit` is set to `auto` (default), temperature units are automatically determined based on the device's location. The following countries use Fahrenheit: United States (US), Bahamas (BS), Cayman Islands (KY), Liberia (LR), Palau (PW), Federated States of Micronesia (FM), and Marshall Islands (MH). All other countries use Celsius.

edge-apps/clock/e2e/screenshots.spec.ts

@@ -16,7 +16,6 @@ const { screenlyJsContent } = createMockScreenlyForScreenshots(
     location: 'New York, NY',
   },
   {
-    theme: 'light',
     override_timezone: 'America/New_York',
     override_locale: 'en',
     openweathermap_api_key: 'mock-api-key',

edge-apps/clock/screenly.yml

@@ -51,13 +51,6 @@ settings:
     help_text: |
       Enter your Google Tag Manager container ID to enable tracking and analytics.
     is_global: true
-  theme:
-    type: string
-    default_value: light
-    title: Theme
-    optional: false
-    help_text: |
-      Select the visual theme for the app ('light' or 'dark').
   unit:
     type: string
     default_value: auto

edge-apps/clock/screenly_qc.yml

@@ -51,13 +51,6 @@ settings:
     help_text: |
       Enter your Google Tag Manager container ID to enable tracking and analytics.
     is_global: true
-  theme:
-    type: string
-    default_value: light
-    title: Theme
-    optional: false
-    help_text: |
-      Select the visual theme for the app ('light' or 'dark').
   unit:
     type: string
     default_value: auto